Force Discharge Function

[SteveDocker]

Hi, can anyone please help with the following?

I have the following Fox ESS equipment installed:

Fox ESS 5kWh Hybrid Inverter (H1-5.0-E ). Firmware recently updated (Master 1.63, Slave 1.02, Manager 1.70).
FOX ESS 4.3 kWh Master Battery (ECS4300H v2.0)
FOX ESS 4.3 kWh Slave Battery (ECS4300H v2.0) x2
No PV solar installed.
Octopus Go EV Tariff and Octoplus Saving Sessions.

Basically, I am trying to achieve the following:

1. Daily Charge 00:31 to 04:29 (to align with the Octopus Go EV night rate tariff).

2. Daily Discharge Option 1 - Immediate Discharge. Commence discharge to home load immediately following the charge period, from 04:30 until either MinSoC (20%) or next charge session (00:30 next day).

3. Daily Discharge Option 2 - Delayed Discharge (to take advantage of Octoplus Saving Sessions). Delay discharge to home load until a specified time, from xx:xx until MinSoC (20%) or next charge session (00:30 next day). We receive xx:xx (Octoplus Saving Session start time) with about 24hrs notice (so far this has been 16:30 or 17:00 for between 1 to 1.5hrs duration). Ideally, this needs to be a template whereby we can just alter the start time as required. This is what I have tried:

Work Model: Self-Use
User-defined:
Strategy Period
Time Period: Start Time: 16:00 End Time: 23:59
Working Mode: Force Discharge
MinSoC: 20%
FDSoC: 20%
FDpwr(w): 5000 (Not sure if this is correct?)

Items 1 and 2 have been working well since installation but when I try to implement/enable Item 3 it does not seem to work and removes all of the daily charge settings so that the battery fails to charge at the next charge period!

Any help would be greatly appreciated.

[Dave Foster]

The strategy periods (item 3), overwrite the normal charge periods (they can also change minsoc settings), and you have to remember to replace them when a strategy has been used.

I prefer to do what you are doing with items 1 & 2, and I have a template set up in strategies to do the force discharge (I just change times if needed), I then enable strategy when I need it, and disable it as soon as it has run - at which point I reset my normal charge periods - which admittedly is fiddly.

I believe that what Foxess want you to use is *just* strategies so for example you would set your Force Charge from 00:30-04:29, followed by a setting of work mode to Self-Use at 04:30

Then you would simply add the Force Discharge item when you want to run an Octoplus saving session.

Have a read of the document that Tony has produced on work modes and strategies ( https://github.com/TonyM1958/HA-FoxESS- ... -work-mode ), it's very clear and concise and hopefully will help.

[SteveDocker]

Many thanks Dave, I'll have a read and try again. Not sure what value I need for FDPwr though?

[Dave Foster]

Many thanks Dave, I'll have a read and try again. Not sure what value I need for FDPwr though?

If you are Force Discharging, you set it to the amount of power you want your batteries to discharge at so for example you only want to export at 2kwh you would set it to 2000 (watts). If you want it to discharge at the maximum power your inverter can handle set it to 6000.

Note that any house load is deducted from this, so if you were discharging at 2000w and the house load was 400w, you would only export at 1600w.

With Force Charging the FDpwr and FDSoc aren't used but they have to be entered to save the strategy, so set FDSoc to 10 and FDPwr to 0.

[SteveDocker]

Thanks Dave. As I don't have solar PV I will not be discharging back to the grid. All I need is to cover the home load, especially during the Octopus saving sessions.